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70 In 2017, the latest year for which data are available, 887 fatal utility pole crashes occurred in the United States, accounting for 914 fatalities. These numbers were about the same as those in recent years but lower than such fatality numbers from a decade or two ago. UOs own the poles involved in these crashes, but most of these poles are located on public road or street rights-of- way, which are the responsibility of STAs or LPAs. Gaps exist in current knowledge on exemplary guidelines related to pole placement. Not enough is currently known about how STAs can effectively identify and track utility pole crashes and high-risk locations and how STAs can implement such methods. Study Purpose This synthesis report is designed to summarize the strategies, policies, and technologies that STAs and UOs employ to address utility pole safety concerns. Information was gathered from a comprehensive review of the literature and also the results from STA surveys. Specific areas of interest for this synthesis report include methods to identify problem poles and high-risk locations, pole-placement policies, strategies and countermeasures to reduce the risk of pole-related collisions and resulting injuries and deaths, and available funding sources for implementing countermeasures. Case studies were also developed for exemplary STAs and UOs, highlighting some of their utility pole safety activities. Results of the STA Survey Of the 50 STAs contacted for this study, 92% (46 of 50) responded to the written survey or answered the survey questions during phone interviews. Valuable information was acquired regarding the current state of practice with respect to safety procedures for utility poles. The survey identified safety programs, guidelines, and countermeasures that STAs employ to improve utility pole safety. Utility Placement Guidelines Although a great majority of STAs referred to AASHTO guidance such as its Green Book (AASHTO 2011a) and Roadside Design Guide (AASHTO 2011b), only a few states have devel- oped their own guidelines specifying their own criteria regarding pole-placement offset. Only a few STAs have utility placement guidelines that give specific consideration to siting poles with an understanding of trying to minimize crash risk. A few STAs offer additional guidance, such C H A P T E R 1 1 Conclusions
Conclusions 71 as minimum pole offset distances from the road in urban areas (e.g., 5 feet from the road) and in rural areas (e.g., 10 feet from the road), or simply avoid situating poles in high-risk areas, such as close to the road on the outside of horizontal curves, at the top of a T-intersection, at a lane drop, or in a median or traffic island. Exceptions to Pole-Placement Guidelines Many STAs indicated that, in practice, an exception protocol for the established clear zone requirements is sometimes necessary. Several agencies reported that pole-placement exceptions were determined during the design process, before giving permission to UOs to install poles. Some of the most common answers regarding exception policies noted that pole removal would be too costly or would impose an extreme hardship. Another common basis for granting an exception stemmed from situations of inadequate right-of-way or topography that would not allow a safe installation (e.g., steep slopes). Another response noted that an exception would likely be granted to a UO if the exception does not pose a safety concern and is in the best interest of the UO and the state DOT. At least one STA stated that it would not allow poles to be located within the clear zone under any circumstances. Several STAs observed that exceptions are determined âon a case-by-case basis,â and some indicated that poles may need to be moved outside of the right-of-way if they are too close to the road. Another STA reported that exceptions are rarely granted because all pole placements must meet AASHTO clear zone requirements. Utility Pole Crashes All but 7 of the 46 states responding to the survey had the capability to identify whether a police officer coded a utility pole as the type of object struck for a specific crash. However, when asked about the total number of utility pole crashes for a given year, most states either could not produce this information or made a special request to the crash analysis unit to obtain the data. The survey also found that reporting on the number of utility pole non fatal crashes is inconsistent from state to state because of different crash reporting thresholds and because some states combine utility poles and light poles under one category on crash reporting forms. Based on survey responses, a reasonable conclusion is that some states do have information on utility pole high-crash sites, usually gathered when they conduct a site-by-site investigation of locations with a high number of crashes and sometimes when they select countermeasures (such as guardrail installation) to address the crash problem. Interestingly, of the 887 fatal utility (plus light) pole crashes in the United States in 2017, more than half of these fatalities (465) occurred in 10 of the 50 states (NHTSA 2018): â¢ Florida (84) â¢ Texas (69) â¢ California (57) â¢ Pennsylvania (56) â¢ Tennessee (42) â¢ North Carolina (38) â¢ Illinois (36) â¢ New York (28) â¢ Georgia (28) â¢ Indiana (27). Of course, these 10 states also rank among the states with the largest populations and the highest total miles driven.
72 Utility Pole Safety and Hazard Evaluation Approaches Tracking High-Risk Poles Only four states indicated that their STAs routinely track locations with a high number of utility pole crashes. A few states noted that they have computer capabilities (such as mapping tools and computer databases) that enable them to conduct searches to identify sites that experience high numbers of utility pole crashes. Several other STAs reported that they did not specifically track utility poles with a history of vehicle collisions, but they explained how utility poles with a history of being struck might be determined through another process. For example, if a site or roadway section is identified as at high risk of crashes, the STA reviews crashes in that section in more detail and evaluates them to assess the possible effectiveness of pole-related countermeasures. Identifying High-Risk Poles Of the 46 participating STAs, 14 noted that they had a process in place to identify high-risk poles based on their placement and before they were struck. Examples of such sites include poles at lane drops, at intersections, close to the outside of horizontal curves, and too close to the road at other locations, especially on high-volume roads. In addition, STA responses indicated the following types of poles that would be detected: â¢ 11 STAs: poles in the clear zone or too close to the roadway â¢ 8 STAs: poles outside of a horizontal curve â¢ 6 STAs: poles at or near an intersection â¢ 6 STAs: poles at or near a lane drop (as part of the process to identify poles in high-risk locations). Countermeasures in Use The selection and implementation of safety measures to address locations experiencing utility pole crashes typically are the responsibility of the traffic engineering or safety engineering office of an STA. Of the 46 responding states, the countermeasures most often cited as options for treating utility pole safety problems were as follows: â¢ Guardrails or guiderails (31 states) â¢ Crash-attenuation barrels (10 states) â¢ Shoulder widening or paving (15 states) â¢ Rumble strips (19 states) â¢ Pole-visibility features (25 states) â¢ Steel-reinforced safety poles (7 states) â¢ Underground utility lines (23 states) â¢ Shared utility agreements (21 states). New Jersey mentioned that it uses fiberglass poles in certain situations because they shatter on impact from a motor vehicle, resulting in a lower risk of severe injury to vehicle occupants when compared to steel and wooden poles. Funding Improvements for utility pole safety can be funded by various federal, state, local, and other sources of financing. A total of 32 STAs confirmed using federal funds, and 17 of those states specifically cited HSIP funding. In addition, 25 STAs noted state funding as part of their safety improvement resources; such sources included SHSP, matching, state maintenance, spot safety improvement, and state safety funds. Nine STAs employed local financing as a partial match for certain projects. Four STAs reported using âother fundsâ for relocating utility poles.
Conclusions 73 Local and Utility Owner Policies Of the 46 STAs that participated in the survey, 35 STAs answered that they knew of no local agencies or utility providers that have developed their own utility pole safety policies. Nine STAs mentioned local agencies that may have developed their own guidelines. One STA respondent stated, âSome cities and counties have changed policies to only allow underground facilities.â Six STAs were aware of UOs that have developed their own safety programs or guidelines. Factors Related to Utility Pole Crashes An extensive number of research studies have been conducted since the 1970s on utility pole crash factors and potential countermeasures, but the amount of research on this topic has dimin- ished in recent years. Some of the roadway and pole factors documented by research as related to a higher frequency of utility pole crashes are higher volume of vehicular traffic (AADT), larger number of poles per mile within the highway right-of-way, closer pole offset (i.e., narrower buffer between the pole and the roadway), more roadway curvature (i.e., sharper horizontal curves or steeper vertical grades), lower pavement skid resistance, and lack of proper curve superelevation. The location of a pole at high-risk spots (such as at an intersection, at or near a lane drop, or directly outside of a horizontal curve) also increased the chance of a collision with a utility pole. Research has found that approximately 50% of utility pole crashes result in at least one person being injured, with 1% to 2% of crashes causing a fatality. A greater chance of death or serious injury from a utility pole collision was associated with higher impact speeds, greater pole circumference, and certain pole types. Specifically, impacts with wooden poles were usually more severe than collisions with metal poles, but the metal poles used in the research typically incorporated some type of breakaway or frangible base, installed to reduce the severity of a vehicle impact. Crashes along roadway sections typically are categorized as more severe than those at inter- sections, likely the consequence of lower vehicle speeds at intersections. Vehicle and occupant factors associated with more severe outcomes include certain vehicle characteristics (e.g., smaller vehicles), impact configuration (i.e., side impacts, which are more severe than head-on colli- sions), and failure of occupants to use restraints. Utility Poles at High-Risk Locations A utility pole in a high-risk site is one in a location within the roadway environment where the pole carries an above-average risk of being struck by an errant motorist and where serious injury or death is a likely outcome of such a collision. Estimates have indicated that no more than 1/10 of 1% (0.001) of existing poles nationwide are in such high-risk sites. In other words, utility pole safety could be greatly enhanced across the country by addressing this small percentage of high-risk poles. Examples of high-risk locations include those with poles that are close to intersections, on the outside of horizontal curves (and close to the road), immediately after (and in line with) a lane drop, in the roadway median or traffic island, and adjacent to reverse curves. Utility poles in these types of sites are considered to be in high-risk locations and are typically identified as needing safety measures. Cost-Effectiveness Treatments On the basis of their research from the 1980s, Zegeer and Parker (1983) created a utility pole crash-prediction model based on traffic volume (ADT), pole density, and pole offset from the road. This crash-prediction model led to the development of estimated crash effects (CMFs) for
74 Utility Pole Safety and Hazard Evaluation Approaches countermeasures such as moving poles further from the road (i.e., pole relocation), reducing the number of poles within a roadway section (i.e., increased pole spacing), arranging multiple- use poles (i.e., removing a line of poles on one side of the road and doubling up lines on poles on the other side), burying utility lines underground (combined with pole removal), and using breakaway poles. Based on the CMF values, cost of countermeasures, and human and financial costs of various pole-related crashes, cost-effectiveness charts and tables were reported, similar to those developed in the study by Zegeer and Parker (1983). The factors related to expected crashes and countermeasure effectiveness included ADT, pole density, and pole offset. In addition, other factors included a measure of other roadside features (termed a roadside rating) that affect how many crashes might still occur if a pole is removed, repo- sitioned, or altered and the type of pole (telephone, electric, one-phase or three-phase, transmis- sion pole). Most of the specific pole-related treatments (e.g., pole relocation, underground lines, multiple-use poles, breakaway poles) were calculated to be cost-effective (with a benefit-cost ratio greater than 1) for most roadway situations, particularly where the utility poles are currently within about 5 or 10 feet from the roadway and the traffic volume is moderate or higher (e.g., 10,000 ADT vehicles). This assessment was particularly valid for relocating poles (from 5 feet or closer to at least 20 feet from the road) and for burying utility lines underground (with pole removal). Multiple-use poles (running lines on only one side of the road) were often cost-effective, but reducing pole density simply by increasing pole spacing was rarely cost-effective. Treatments involving telephone poles were far less costly than those for poles carrying electric lines and therefore mathematically more likely to be cost-effective compared to similar treat- ments for larger electric transmission poles and lines. The use of breakaway devices on poles was thought to probably be cost-effective for individual poles in high-risk locations although CMFs for this treatment were only estimates and not as well known. Because of the large size of transmission poles and the associated costs for moving them, none of the countermeasures that repositioned these poles or lines was calculated as cost-effective. In such instances, guard- rails or crash-attenuation devices would generally be much more advisable and more likely to be cost-effective. The previous cost-effectiveness discussions should be read with caution because the costs of both crashes and countermeasures have increased since the referenced Zegeer and Parker (1983) study. An analyst could employ the same CMF values as reported herein, with more up-to-date costs for crashes and countermeasures, to compare the benefit-cost ratio of treatment options for a specific case. STA and UO Utility Pole Treatment Options Many practical solutions and countermeasures are available to address utility poles in high- risk locations, including those summarized in this section. UO treatment options include removing poles, repositioning poles to less high-risk loca- tions, or both; decreasing the number of poles through multiple-use poles or expanded pole spacing; increasing lateral pole distance from the pavement travel way; and burying utility lines underground. STAs can implement some measures to keep vehicles on the roadway and away from poles, such as pavement markings, signs and roadway lighting, pavement delineation measures (e.g., edge- line paint stripes and raised pavement markers), edge-line rumble strips, improved pavement skid resistance, wider lanes, wider and paved shoulders, enhanced curve safety (e.g., improved superelevation, additional in-advance curve warning and chevron signs, straighter curves), additional pavement skid treatments, and other less common techniques.
Conclusions 75 STAs can also use safety devices to reduce the severity of crashes when vehicles do leave the roadway. Such devices include composite yielding poles, steel-reinforced safety poles, crash cushions, concrete barriers, guardrails and crashworthy guardrail terminal ends, breakaway guy wires, buried duct networks for utility cables, and other less frequently used methods. Example of a Logical Approach to a Utility Pole Safety Program TRB State of the Art Report 9 explains an approach for reducing utility pole-related fatalities and serious injuries, as developed and described by Ivey and Scott (2004). This plan includes the following strategic approach options: â¢ Best Offense. This approach identifies where an atypically high number of collisions are occurring, assesses available countermeasures, prioritizes these high-risk poles for treatment, and implements the improvements. â¢ Best Bet. This approach prioritizes potentially hazardous poles and roadway sections, possibly using statistical prediction algorithms, before a crash history develops and also implements appropriate improvements. â¢ Best Defense. This approach complements the first two strategies and entails striving to meet the recommendations of the Roadside Design Guide (AASHTO 2011b) and Ivey and Scott (2004). Examples of Utility Pole Safety Initiatives Based on information in the literature and in survey responses, several STAs and UOs were selected for development of more detailed case studies. The STAs include Washington State, New Jersey, Georgia, and North Carolina. In addition, one anonymous STA is discussed in a case example because its utility pole safety program was scaled back in recent years in response to challenges that the STA faced in dealing with UOs in the state. This case example is included with the thought that other STAs might relate to similar challenges and develop their own tailored approaches to address them. To protect their privacy, four unnamed UOs were selected to provide documentation of their utility pole safety practices and policies. Appendix F cites an Ivey and Scott (2004) appendix where Scott describes a recommended utility pole crash-reduction program for STAs. Appendix G details specific STA utility pole safety guidance from several states. Implications of Synthesis Much was learned from the literature review and from the STA survey responses. Specifically, only a few (less than half) of the STAs have policies or guidelines that focus on utility pole place- ment going beyond the AASHTO Green Book (2011a) and Roadside Design Guide (2011b) and that also appear to actively identify and treat utility pole safety problems. Part of the challenge with STAs is diffuse authority: safety issues related to utility poles were under the jurisdiction of at least three different departments in most STAs or transportation departments. Specifically, each state delegated the task to a department that handles utility accommodation and works with the UOs in the state to apply pole-placement guidelines. STAs usually have a separate transportation or safety engineering office that holds responsibility for identifying high-crash and high-risk locations and for conducting engineering studies to select countermeasures to reduce the risk of potential crashes. During this process, safety engineers normally review all types of crashes and highway risks (at least annually) but usually review utility pole crashes only if they represent a cluster of crashes at a previously identified high-crash or high-risk location.
76 Utility Pole Safety and Hazard Evaluation Approaches In addition, in most STAs, another office typically produces crash summaries and conveys crash trends and high-crash location information to the safety engineers. This safety engineering data office may also secure funding for implementing recommended treatments. Most of the STA engineers interviewed did not know offhand the number of utility pole crashes in their state for 2016. Some STAs made a special request for another department to conduct a data search just to obtain that information for this synthesis survey. Thus, different offices within a given STA managed the problem of utility pole safety in many cases. However, as many as 20 STAs did have some utility pole safety policies and procedures, including pole-placement guidelines, processes to identify and treat poles in high-risk locations, or both. Many states use countermeasures such as installing guardrails, edge-line rumble strips, low concrete barriers, and other barrier types to address roadside safety problems, which may include utility pole crash issues. Based on the interaction with STAs during this synthesis report process, less than a dozen undertook ongoing systematic utility pole safety activities. Very few UOs had at least adopted guidelines to consider removing poles in high-risk locations, although steel-reinforced safety (breakaway) poles are employed in about six states, according to STA contacts. In addition to being governed by STA pole accommodation guidelines in each state, UOs are also routinely subject to the provisions of the National Electrical Safety Code (Institute of Electrical and Elec- tronic Engineers 2017), which designates that UOs site poles a minimum of 18 inches from the edge of curb. However, safety research has indicated that an offset distance of approximately 10 feet (compared to siting poles approximately 2 feet from the roadway edge) is needed to reduce a great majority (up to 70 to 80%) of utility pole crashes. In short, during the roughly 15 years since TRB State of the Art Report 9 (Ivey and Scott 2004) was published, neither the STAs nor the UOs appear to be making much progress toward improving practices for utility pole safety. Most STAs still do not have routine procedures to specifically identify locations with clusters of utility pole crashes, nor do most of the states categorize utility poles in high-risk sites. In one case example (for the anonymous STA), some very proactive policies addressed utility pole safety as recently as 2004, but those policies had been largely excised from more recent editions of the stateâs utility manual because of challenges in implementing those procedures. Utility poles stand as the rigid obstacle that our society in general recognizes but only a few STAs have addressed systematically, even with a long-term goal of reducing highway fatalities and severe injuries. The Roadside Design Guide (AASHTO 2011b) observes that through decades of safety research and experience, the application of the âforgiving roadsideâ concept has been refined to the point where roadside design constitutes an integral part of the transportation design process. AASHTO consistently has recommended the following hierarchy for reducing roadside obstacles: 1. Remove the obstacle 2. Redesign the obstacle so that it can be safely traversed 3. Relocate the obstacle to a point where it is less likely to be struck 4. Reduce the impact severity by using an appropriate breakaway device 5. Shield the obstacle with a longitudinal traffic barrier designed for redirection (or use a crash cushion) 6. If the previous alternatives are not appropriate, delineate the obstacle. For every utility pole that is documented as occupying a high-risk location, at least one and usually several of these listed options are reasonable solutions to achieve the objective of a forgiving roadside. If the hazardously located utility poles in the nation are not moved or addressed with countermeasures known to improve safety, a historical total of 100,000 utility pole-related fatalities and an estimated 3 million injuries may be reached by yearend 2020 or shortly thereafter.
Conclusions 77 Current Gaps in Knowledge Based on the review of literature and input from STA surveys, an understanding of the gaps in current knowledge sharpened. For example, gaps exist on the current economic analysis metrics for various treatment options that can improve the safety of individual utility poles or a line of poles along a highway. In particular, no known published information addresses the current costs for pole relocation, multiple-use poles, underground lines, increased pole spacing, and installation of breakaway poles (e.g., fiberglass poles, steel-reinforced safety poles) for different types of utility lines and poles (e.g., telephone versus electric versus transmission poles). Also, crash effects (CMFs) should be updated for these treatments and for STA treatments such as guardrails, cash attenuators, and shoulder improvements. Similarly, CMFs for horizontal curve and intersection countermeasures to improve utility pole safety must be better quantified. Such current information is necessary to support updating the benefit-cost analysis from the Zegeer and Parker (1983) study. In addition, very little is known concerning the safety of various other types of poles, such as traffic signal support poles and buddy poles (two poles installed close together for added sup- port that may cause a more severe crash outcome when struck). Furthermore, actions should be identified that can contribute to agencies acquiring a better understanding of utility pole safety issues that will lead to positive change. Future Research Areas Based on these gaps in knowledge on utility pole safety, several potential research areas are identified, most notably the following: 1. Updated information should be gathered on countermeasure installation costs and annual maintenance costs for relocating poles, reducing pole density (i.e., installing multiple-use poles, increasing pole spacing in hazardous locations), running utility lines underground, and using breakaway poles (i.e., fiberglass and steel-reinforced safety poles). This information collection should be performed for all types of utility poles and lines, including telephone poles and various levels of electric distribution poles and lines. Updated benefit-cost ratios for implementing various pole-related treatments should be developed based on these updated countermeasure costs, annual maintenance costs, and up-to-date costs for utility pole crashes. 2. A formal evaluation of steel-reinforced safety poles, fiberglass yielding poles, and other yielding utility poles would be useful. Regarding steel-reinforced safety (breakaway) poles, FHWA previously managed a demonstration project that paid for the cost of retrofitting selected utility poles in high-risk locations. That initiative led to four states participating in the project. As a result, the selected utility poles were converted to breakaway features. A similar demonstration, only with a provision for other breakaway pole designs (such as the fiberglass yielding poles), was conducted in New Jersey, and more information on other comparable designs would be informative. Moreover, various types of barriers, barrier end treatments, and similar devices could be evaluated as part of this effort. Recommendations would be helpful regarding the feasibility and effectiveness of various types of countermeasures when used to treat high-risk poles that cannot easily be moved or removed. 3. One helpful study could identify the factors and conditions that led some STAs and UOs to recognize the importance of addressing utility pole safety problemsâas well as the measures that might be effective in convincing other agencies to more aggressively implement policies and practices to improve utility pole safety. An analysis should be performed on how dedi- cated funding could be made available to STAs, LPAs, and UOs for expenditures on safety improvements related to roadside and utility pole safety.
78 Utility Pole Safety and Hazard Evaluation Approaches 4. Model policies should be developed for STAs and UOs that go beyond the guidance in the AASHTO Green Book (AASHTO 2011a) and the Roadside Design Guide (AASHTO 2011b) and are suited to the specific safety needs of each jurisdiction. The guidance could consider current knowledge based on roadside safety literature with respect to the crash risks associ- ated with various pole offsets from the curb (urban areas) and from the roadway edge (rural areas). The guidance could also incorporate updated data about the types of high-risk loca- tions, including risks at lane drops, in medians and traffic islands, at horizontal curves, and at intersections, among others. 5. Research should define and document the various methods that safety officials can employ to track utility pole crashes in an STA and an LPA. Methods could also be documented for the identification of high-risk poles based on location in the highway environment. This study could result in recommendations to STAs and LPAs on how to implement such procedures to identify not only high-crash but also high-risk utility poles. Case studies of STAs that currently use these procedures could also be helpful. 6. A study would be useful regarding box-span signals at high-risk intersections and their crash history. The relative safety of other roadside obstacles could also be studied, including buddy polesâtwo poles installed close together for added support that may cause a more severe crash if struck by a motor vehicle. Potential countermeasures could be developed to improve the safety of such objects.